Electric motor fuel pumps are widely used to supply fuel to operating internal combustion engines, such as in automotive applications. A fuel pump is typically disposed within a fuel tank and has a lower inlet end for drawing fuel from within the tank and an upper outlet end for outputting drawn fuel under pressure to the engine. Examples of fuel pumps of this general type are illustrated in U.S. Pat. Nos. 5,257,916, and 6,231,318. As shown in FIG. 8, a prior art fuel pump 210 includes a cylindrical metal housing 212 that connects to an inlet cover 214 at a lower inlet end 216 and to an outlet cover 218 at an upper outlet end 220. Although not shown in the figure, there are several components within the housing 212 and between the covers 214, 218. Stacked axially from the lower inlet end, there is a pump assembly typically including an impeller, ring, and pump plate, an electric motor including a flux tube, stator, and armature with an axial commutator, and an armature cover between the armature and the outlet cover. As shown in FIG. 8, the outlet cover 218 includes an axially-projecting male outlet 222 for connecting to an outlet hose (not shown) and also includes terminal blades 224 for connecting to an electrical connector (not shown).
In general, the electric motor of a typical fuel pump is connected to a source of electrical power for driving the armature about its axis of rotation. The armature cover includes the terminal blades, which are fixed thereto and which communicate with axially-extending internal pockets of the armature cover. Internally, the armature cover includes the pockets for housing elongated carbon brushes that are spring-loaded into contact with the axial commutator. The brushes are spring-loaded by axially-extending compression springs that are disposed between upper ends of the carbon brushes and bottoms of the pockets. In other words, each compression spring and brush is aligned in series along a common operational axis and is disposed parallel to the axis of rotation of the armature. The terminal blades are in electrical contact with the axially extending springs, carbon brushes, and commutator, in order to power the electric motor of the fuel pump.
In use, such a state of the art fuel pump is typically disposed within an automotive fuel tank so that their axis extends generally vertically. Automobile designers find it increasingly desirable to package fuel tanks and, thus, fuel pumps, in vertically more confined spaces such as underneath a rear seat of a vehicle. Therefore, the fuel tank and fuel pump must be as axially short as possible. But, current fuel pumps are too axially long to be packaged in such a location. For in-tank vehicle applications, these fuel pumps must also have a small maximum diameter which is usually less than about 2 inches and typically about 1½ inches.